posted on 2014-12-01, 00:00authored byMonika Pawłowska
Purpose The goal of the study was to determine to what extent 3 proposed markers of language impairment (LI) in English (verb tense, nonword repetition, and sentence repetition) accurately distinguish affected and unaffected English-speaking individuals.
Method Electronic databases were searched for diagnostic accuracy studies involving the 3 markers. Quality of relevant studies was described. Numbers of true and false positives and negatives were extracted and used to calculate likelihood ratios (LRs).
Results Thirteen studies met the selection criteria. The majority were based on clinically ascertained samples. Pooled LRs and 95% confidence intervals (CIs) for tense (LR+) and sentence repetition (LR+ and LR?) were suggestive of presence (LR+) or absence (LR?) of LI. Wide CIs around the value of inconsistency I2 index reduced reliability of pooled values for sentence repetition. High between-study heterogeneity precluded pooling of LR values for tense (LR?) and nonword repetition (LR+ and LR?).
Conclusion The limited evidence available suggests that the proposed markers may be at best suggestive of LI in English. Future research may refine existing marker tasks to increase their accuracy and test the most promising tasks in unselected samples of participants with and without LI.
Funding
Lindsay Anderson and Brynna Trowbridge assisted with database searches and ratings of study quality. Partial reports were presented at the SLI (Specific Language Impairment) Diagnosis, Prognosis, Intervention conference in Warsaw, Poland, in July 2012, and at the American Speech-Language-Hearing Association Convention in Chicago, IL, in November 2013.